‘Kakegawa AU18’ originated from a hybridization between Osteospermum ‘Brightside’ (U.S. Plant Pat. No. 10,596) and an unnamed Osteospermum breeding line (unpatented) of unknown origin in Misato, Japan. ‘Brightside’ was chosen for its ability to flower under short-day conditions. In 2001, the two Osteospermum lines were crossed and embryo rescue was performed in order to obtain viable offspring. Ten F1 plants were obtained using this technique.
The F1 plants were evaluated in Misato, Japan in 2002. Criteria for selection included compact growth habit, ability to bloom under short-day, warm conditions, white flower color and basal branching. In 2002, one single-plant selection was made based on the above criteria and vegetatively propagated. The selection subsequently was named ‘Kakegawa AU18’ and found to reproduce true to type in successive generations of asexual propagation.